def countPrimes(n: int) -> int:
    def check(number):
        for i in range(1, number):
            if (number % i) == 0:
                return False
        return True

    num = 0
    for i in range(n):
        is_prime = check(i)
        if is_prime:
            num += 1

    return num 

print(countPrimes(10))